Linux-2.6.12-rc2
[linux-2.6.git] / crypto / crypto_null.c
1 /* 
2  * Cryptographic API.
3  *
4  * Null algorithms, aka Much Ado About Nothing.
5  *
6  * These are needed for IPsec, and may be useful in general for
7  * testing & debugging.
8  * 
9  * The null cipher is compliant with RFC2410.
10  *
11  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  */
19 #include <linux/init.h>
20 #include <linux/module.h>
21 #include <linux/mm.h>
22 #include <asm/scatterlist.h>
23 #include <linux/crypto.h>
24
25 #define NULL_KEY_SIZE           0
26 #define NULL_BLOCK_SIZE         1
27 #define NULL_DIGEST_SIZE        0
28
29 static int null_compress(void *ctx, const u8 *src, unsigned int slen,
30                          u8 *dst, unsigned int *dlen)
31 { return 0; }
32
33 static int null_decompress(void *ctx, const u8 *src, unsigned int slen,
34                            u8 *dst, unsigned int *dlen)
35 { return 0; }
36
37 static void null_init(void *ctx)
38 { }
39
40 static void null_update(void *ctx, const u8 *data, unsigned int len)
41 { }
42
43 static void null_final(void *ctx, u8 *out)
44 { }
45
46 static int null_setkey(void *ctx, const u8 *key,
47                        unsigned int keylen, u32 *flags)
48 { return 0; }
49
50 static void null_encrypt(void *ctx, u8 *dst, const u8 *src)
51 { }
52
53 static void null_decrypt(void *ctx, u8 *dst, const u8 *src)
54 { }
55
56 static struct crypto_alg compress_null = {
57         .cra_name               =       "compress_null",
58         .cra_flags              =       CRYPTO_ALG_TYPE_COMPRESS,
59         .cra_blocksize          =       NULL_BLOCK_SIZE,
60         .cra_ctxsize            =       0,
61         .cra_module             =       THIS_MODULE,
62         .cra_list               =       LIST_HEAD_INIT(compress_null.cra_list),
63         .cra_u                  =       { .compress = {
64         .coa_compress           =       null_compress,
65         .coa_decompress         =       null_decompress } }
66 };
67
68 static struct crypto_alg digest_null = {
69         .cra_name               =       "digest_null",
70         .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST,
71         .cra_blocksize          =       NULL_BLOCK_SIZE,
72         .cra_ctxsize            =       0,
73         .cra_module             =       THIS_MODULE,
74         .cra_list               =       LIST_HEAD_INIT(digest_null.cra_list),   
75         .cra_u                  =       { .digest = {
76         .dia_digestsize         =       NULL_DIGEST_SIZE,
77         .dia_init               =       null_init,
78         .dia_update             =       null_update,
79         .dia_final              =       null_final } }
80 };
81
82 static struct crypto_alg cipher_null = {
83         .cra_name               =       "cipher_null",
84         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
85         .cra_blocksize          =       NULL_BLOCK_SIZE,
86         .cra_ctxsize            =       0,
87         .cra_module             =       THIS_MODULE,
88         .cra_list               =       LIST_HEAD_INIT(cipher_null.cra_list),
89         .cra_u                  =       { .cipher = {
90         .cia_min_keysize        =       NULL_KEY_SIZE,
91         .cia_max_keysize        =       NULL_KEY_SIZE,
92         .cia_setkey             =       null_setkey,
93         .cia_encrypt            =       null_encrypt,
94         .cia_decrypt            =       null_decrypt } }
95 };
96
97 MODULE_ALIAS("compress_null");
98 MODULE_ALIAS("digest_null");
99 MODULE_ALIAS("cipher_null");
100
101 static int __init init(void)
102 {
103         int ret = 0;
104         
105         ret = crypto_register_alg(&cipher_null);
106         if (ret < 0)
107                 goto out;
108
109         ret = crypto_register_alg(&digest_null);
110         if (ret < 0) {
111                 crypto_unregister_alg(&cipher_null);
112                 goto out;
113         }
114
115         ret = crypto_register_alg(&compress_null);
116         if (ret < 0) {
117                 crypto_unregister_alg(&digest_null);
118                 crypto_unregister_alg(&cipher_null);
119                 goto out;
120         }
121
122 out:    
123         return ret;
124 }
125
126 static void __exit fini(void)
127 {
128         crypto_unregister_alg(&compress_null);
129         crypto_unregister_alg(&digest_null);
130         crypto_unregister_alg(&cipher_null);
131 }
132
133 module_init(init);
134 module_exit(fini);
135
136 MODULE_LICENSE("GPL");
137 MODULE_DESCRIPTION("Null Cryptographic Algorithms");